Hi all

I know that the temp of a Sunsynk 5kW has been discussed in several threads here. But I thought I'd share this nonetheless.

I am running 2x Sunsynk 5kW (one with 4.5kW on a single MPPT and the other with 2.3kW on each MPPT). As I thought that both inverters were running a bit hot, I have previously mounted a 120mm PC fan underneath each inverter to have air blow up along the passive heatsink. And with the inverter with the 2 strings connected still running a bit hotter than the other one, I have also placed 2x 140mm PC fans on top of the inverter, sucking air up along the back heatsink.

Yesterday morning my power supply for those fans failed around 03h15. I only noticed around lunchtime and put in a replacement power supply around 13h00 (after my batteries were full). Without the fans yesterday, my inverter temp peaked at 72.5 degrees. Today with fans, my temp peaked at 61.0 degrees. Rest of variables (load, sun, ambient temp, etc.) similar across both days.

To me a clear indication that the Sunsynk benefits from additional cooling

I saw this post a few weeks back so checked my Sunsynk 5K temps, they were regularly over 50°C, even reaching 58 occasionally.
About a week ago I installed 2 x 92mm 12vdc fans below the heatsink blowing up. I have the fans connected to a smart switch which I control from Home Assistant.
I've set it to turn the fans on when the inverter (using the "Radiator" temp) temp reaches 45°C and turns off the fans when the temp drops back below the 45°C for 5 minutes. I also have a wall mounted 220v fan (like a desk fan but mounted to the wall) in the garage connected to the same smart switch, I figure moving some of the hot garage air around would be useful too...
Since setting this up my inverter temp now seldom hits 46.5°C regardless of air temp (air temp has been over 30°C in the past week), definite improvement.
I have bought spare 92mm fans to replace the current ones when they fail...

Do the 5kw not have built in fans like the 8kw?

35 minutes ago, Chris_S said:

Do the 5kw not have built in fans like the 8kw?

I think there are several revisions of the 5kW. If I am not mistaken, the first one did have fans on the outside by the heatsink. The version that I have only has a passive external heatsink.

I have to admit that I have no idea about internal fans

On 2023/01/19 at 10:28 AM, RhysMcW said:

I've set it to turn the fans on when the inverter (using the "Radiator" temp) temp reaches 45°C and turns off the fans when the temp drops back below the 45°C for 5 minutes.

Please would you share this HA code with me?

I am also concerned about the temperatures. Mine gets up to nearly 80!!! I can't believe this is good?? Seems a pity to have to install fans on a piece of kit that cost close to R30k!

 

I don't have heat problems with my LXP (Luxpower) which has no fans, because I only have 1500 watts of PV on one MPPT at the moment. What I have made though is a chimney which fits on top to improve the draft upwards and it does make a difference. I will experiment with taller chimneys when I add more PV. Maybe experiments with cardboard chimneys to aid updraft could be fun and cost nothing.

On 2023/01/25 at 2:54 PM, Terminal3k said:

Please would you share this HA code with me?

@Terminal3k sure, should be attached - it's done in Node Red.
You'll probably need to redo the entity associations unless yo happen to use the same names I'm using...

Inverter Cooling Fans flows.json